The present invention relates to an improved process for the preparation of chlortetracycline-containing compositions suitable for incorporation in animal feed.
Antibiotics, such as tetracyclines, are used as growth promoters and feed efficiency promoters in animals such as poultry and livestock, and for therapeutic and prophylactic disease control in animals such as poultry and livestock, fish, domesticated pets, and so forth. Such antibiotics are typically formulated in an animal feed premix or animal feed supplement containing the antibiotic and an edible carrier or diluent. These premixes or animal feed supplements may then be mixed with a sufficient quantity of an appropriate animal feed (e.g., livestock, poultry, fish, pet and/or other animal feed) to provide a final animal feed formulation having the desired level of active compound in the feed.
Prior art chlortetracycline-containing animal feed supplements prepared through normal fermentation and dehydration of the mycelium meal provide, at maximum, chlortetracycline potencies of about 26% to 28% by weight. The highest concentration currently available in a standardized feed supplement is 22%. (Since chlortetracycline hydrochloride is the reference standard for chlortetracycline feed grade materials, all chlortetracycline concentrations and percentages stated herein, unless indicated otherwise, are calculated as the hydrochloride equivalent, regardless of the form present (e.g., the free base, complexes or salts other than the hydrochloride, etc.)). In order to obtain higher chlortetracycline concentrations, it is possible add pure crystalline chlortetracycline hydrochloride USP to the mycelium meal to raise the potency. This, however, is not economical. Furthermore, because chlortetracycline hydrochloride is water soluble, there is a question of stability in finished feeds containing moistures of 10% or higher.
It would therefore be desirable to provide a chlortetracycline-containing animal feed premix or animal feed supplement suitable for use in the veterinary, animal nutrition, and animal husbandry arts that can be prepared directly from a fermentation product and that can be prepared in a high concentration without requiring the addition of the antibiotic in pure form and that has improved stability over chlortetracycline hydrochloride feed supplements.
The present invention provides an improved process and apparatus for the preparation of a fermentation cake or mycelium meal material containing chlortetracycline. The present invention also relates to the chlortetracycline-containing fermentation cake or mycelium meal material so produced and chlortetracycline-containing animal feed additives derived therefrom. It has been discovered that the procedures in accordance with this teaching produce chlortetracycline-containing fermentation products having higher concentrations than possible from prior fermentation/dehydration processes, thus making it possible to produce animal feed supplements which take up less room in feed complexes, require less storage space, reduce packaging and shipping costs, and so forth. The present invention also relates to animal feed compositions prepared in accordance with this teaching.
In certain embodiments, the present invention provides chlortetracycline-containing animal feed additives having a chlortetracycline concentration of about 35% or greater. In preferred embodiments, the present invention provides chlortetracycline-containing animal feed additives having a chlortetracycline concentration of about 40% to about 70%, or greater. In more preferred embodiments, the present invention provides chlortetracycline-containing animal feed additives having a chlortetracycline concentration of about 44% to about 55%.
In additional embodiments, the present invention also relates to methods for preventing or combating microbial infection in animals comprising orally administering to said animals a prophylactic or therapeutic amount of an animal comestible composition comprising a medicated feed supplement according to the present invention. In yet a further embodiment, the present invention relates to methods for increasing feed efficiency, promoting animal growth, and increasing rate of weight gain and in an animal comprising orally administering to said animals an effective amount of an animal comestible composition comprising a medicated feed supplement according to the present invention.